Question

Rohit can finish a work in 30 days Rohit and his friend Rohan working together can do it in 12 days in how many days Rohan do it alone​

Answer 1

Answer:

the answer is 2.5

it is right

Step-by-step explanation:

30 ÷ 12 = 2.5

Answer 2

Answer:

In 20 days Rohan can do it alone.

Step-by-step explanation:

Given,Rohit can finish a work in 30 days.

So, in 1 day Rohit can finish $\frac{1}{30}$ part of work.

It is also given that Rohit and his friend Rohan working together can do it in 12 days.

So,by Unitary method in 1 day they can do $\frac{1}{12}$ part of work.

Now, Rohan can do it alone in one day

$( \frac{1}{12} - \frac{1}{30} ) \\ = \frac{5 - 2}{60} \\ = \frac{3}{60} \\ = \frac{1}{20} \: part \: of \: work$

Therefore,by Unitary method in 20 days Rohan can do 1 complete work.

Some important time and work formulas for you:

Work done = time taken × rate of work

Operating speed = 1 / elapsed time

Time used = 1 / work rate

If the work is done in x number of days, then the work done in one day = 1/x

Total wok = number of days × efficiency

Efficiency and time are inversely proportional to each other.

X:y is the ratio of the number of men needed to do the work, then the ratio of the time required to do their work is y:x.

Time and work related two more questions,

https://brainly.in/question/1957191

https://brainly.in/question/34046376

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